Subject: How to Write Effective Subject Lines

I thought about subject lines long before I got into the email client game. Applying for internships in a worsening economy, (and, later, jobs in a deplorable one) I realized that the subject line of my cover letter was my best chance at winning the ring toss, the surest route out of some beleaguered editor’s 500-deep application folder. Which brings me to the Part 1:

Subject: How to write subject lines to people you don’t know

An email’s subject line is the second thing the recipient sees. If you, the sender, are a stranger, it’s also likely your best chance at getting read. Crafting a good one requires that you a) understand what your audience deems open-worthy, and b) have the chops to convince them that your email is open-worthy. As a job applicant, that may translate to:
Subject: The Top 10 Reasons I Want to Intern for Conde Nast Traveler
Or perhaps:
Subject: print “Meet Claire. She wants to be your lead engineer.” *

Writing a subject line for a marketing email is a little harder, because your recipients are also strangers, and they (usually) know that your email was not written only to them. Here, the subject line needs to focus exclusively on what the email’s contents will offer the recipient, eg this one, from the epicures at Tasting Table:
Subject: The ONE pizza you have to eat this summer
Obviously, that got opened right away. Nicoletta’s, be prepared.

The Obama campaign has been experimenting with a variety of social media and messaging to segment resonance. I applaud them for that. I do not, however, applaud them for subject lines like this:
Subject: So Cool
And
Subject: Hey
Newsletter management platform Mail Chimp conducted a subject line study this year on 200 million emails. The majority of emails with the highest open rates had subject lines that contained timely, useful information and implied benefit for action. Marketing emails are not the time for dangling leads, especially ones as opaque as the Obama campaign’s.

Got it? Great. Now let’s move onto Part 2:

How to write subject lines to people you know

There are three maxims here. The first is that the best subject lines serve as standalone messages. The recipient should only need to open them to reply or view/download attachments.

The second is that the recipient should be able to tell at a glance whether the email merits response or some other action. Some people advocate the usage of acronyms like EOM (end of message) or NNTR (no need to respond), but I think commands or question marks suffice. Eg:
Subject: I will be 5 minutes late to standup. Please proceed without me.
And
Subject: Do you want to go to the Strata Conf Oct 14-16?

The third is that there should be no room for misinterpretation. Subject lines like:
Subject: What do you think about the Strata Conf?
Will result in needless rounds of clarification.

Since I started writing standalones, my thread counts have gone way down. And threads, as everyone knows, make up 50% of your inbox. (Newsletters and notifications make up the other 50%.)**

However, if, after reading all this, you still insist upon using vague and/or messy subject lines--there is another remedy your recipients can use. It's called Gander. It uses social network and sentiment analysis to decide which emails are the ones users should see first. We think it's pretty cool, but then again, we made it. To see if you agree, you can sign up for the beta here.